1. Field of the Invention
The present invention relates generally to industrial heat treating equipment used to strengthen and harden metal alloys, and more specifically to an automated door configuration for use in heat treating furnaces that frees the operator's hands to work with items in the furnace.
2. Description of the Related Art
Heat treating metals in order to enhance their hardness and other physical and metallurgical properties is a process that dates back hundreds of years. Many modern heat treating methods involve the use of furnaces that are used to heat the metal to extreme temperatures in upwards of 2000 degrees Fahrenheit. Subsequent to this heating, the metal is quenched, that is submersed in a liquid such as oil or water, in order to further alter its crystalline structure, resulting in increased strength and hardness. Quite often, however, the design of the heat treating furnaces and quench tanks are such that a poor ergonomic functionality results. As a result, the user is hindered by things such as furnace doors that require a free hand to operate while maneuvering the metal objects and quench tanks or trays that are positioned at a remote location, requiring the user to transport the materials back and forth. Accordingly there is a constant need for new and innovative heat treating furnace designs that allows the user free use of his hands while providing the full functionality of conventional heat treating procedures. The development of the present invention fulfills this need.
A search of the prior art did not disclose any patents that read directly on the claims of the instant invention. However, several references teaching automated door assemblies were discovered. None of these disclosures, however, anticipate or disclose any embodiment that combine the features of the present invention. As a result, none of the prior art precludes the novelty and the utilitarian functionality of the present invention.
Several patents disclose mechanical door opening means wherein the user actuates the door via a foot pedal in order to open a cabinet or the like.
U.S. Pat. No. 5,622,416 issued in the name of Rainey et al.; PA1 U.S. Pat. No. 5,540,012 issued in the name of Clegg; PA1 U.S. Pat. No. 4,911,508 issued in the name of Tillman; and PA1 U.S. Pat. No. 1,109,723 issued in the name of White. PA1 U.S. Pat. No. 5,163,574 issued in the name of Sosan; and PA1 U.S. Pat. No. 5,147,056 issued in the name of Ma. PA1 U.S. Pat. No. 5,058,654 issued in the name of Simmons et al.; and PA1 U.S. Pat. No. 4,026,264 issued in the name of Henriques.
Two patents disclose mechanical door opening means wherein the user opens the door to a trash receptacle via a foot pedal.
All of these disclosures are directed to mechanical means by which doors are opened via a foot pedal. Relying on a variety of linkage lever configurations or, cable and pulley arrangements, these devices transfer the force applied to a foot pedal by the user to the door in order to force it opened. None of these disclosures anticipate the use of a motorized or automated opening force activated by a foot-operated pedal switch.
The following patents describe a portable heating furnace-type devices used in both industrial and domestic settings.
Neither of these patents disclose a heat treating furnace, nor do they anticipate any use related to metal hardening or other heat treatment purposes. Furthermore, neither disclosure includes any mention of any door opening assemblies, whether mechanical or automated.
U.S. Pat. No. 4,658,545 issued in the name of Ingham et al. discloses an automatic door opener and closer wherein conventional entrance/exit doors commonly found in commercial establishments are opened and closed automatically by an opening mechanism powered by an electric motor. The electric motor is connected to a speed reducing, torque increasing mechanism consisting of a series of belts and pulleys that cause a swing lever, attached to the door, to swing the door to the opened or closed position automatically as a person approaches. While this disclosure teaches an automated door opening apparatus, it does not anticipate any use in conjunction with a furnace or any industrial equipment whatsoever. Furthermore, this disclosure is directed to the opening and closing of a hinged door assembly rather than a sliding track type door assembly.
While several features exhibited within these references may be incorporated into this invention, alone and in combination with other elements, the present invention is sufficiently different so as to make it distinguishable over the prior art.